xep-0408.xml

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<!DOCTYPE xep SYSTEM 'xep.dtd' [
  <!ENTITY % ents SYSTEM 'xep.ent'>
%ents;
]>
<?xml-stylesheet type='text/xsl' href='xep.xsl'?>
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<xep>
<header>
  <title>Mediated Information eXchange (MIX): Co-existence with MUC</title>
  <abstract>This document defines an extension to Mediated Information eXchange (MIX) specified in XEP-0369.  It specifies how MIX and MUC can be operated together. </abstract>
  &LEGALNOTICE;
  <number>0408</number>
  <status>Deferred</status>
  <type>Standards Track</type>
  <sig>Standards</sig>
  <approver>Council</approver>
  <dependencies>
    <spec>XMPP Core</spec>
    <spec>XMPP IM</spec>
    <spec>XEP-0004</spec>
    <spec>XEP-0030</spec>
    <spec>XEP-0054</spec>
    <spec>XEP-0060</spec>
    <spec>XEP-0084</spec>
    <spec>XEP-0128</spec>
    <spec>XEP-0198</spec>
    <spec>XEP-0292</spec>
    <spec>XEP-0297</spec>
    <spec>XEP-0313</spec>
    <spec>XEP-0372</spec>
  </dependencies>
  <supersedes/>
  <supersededby/>
  <shortname>MIX-MUC</shortname>
  &ksmithisode;
  &skille;
  <revision>
    <version>0.2.0</version>
    <date>2021-03-09</date>
    <initials>@mathieui</initials>
    <remark><p>Fix reference to MIX-CORE namespaces</p></remark>
  </revision>
  <revision>
    <version>0.1.1</version>
    <date>2020-12-01</date>
    <initials>gh/@mathieui</initials>
    <remark>Fix minor XML formatting issues</remark>
  </revision>
  <revision>
    <version>0.1.0</version>
    <date>2018-05-21</date>
    <initials>sek</initials>
    <remark><p>
      Split out from MIX 0.10.0;
    </p></remark>
  </revision>

</header>
<section1 topic='Introduction' anchor='intro'>
  <p>The Mediated Information eXchange (MIX) protocol framework and core capabilities are specified in &xep0369; (MIX-CORE).
    MIX can be used independently of &xep0045; (MUC).
   </p>
 <p>
   It may be desirable to operate a service that provides MIX and MUC together.   This specification specifies three options for achieving this.
 </p>
</section1>





<section1 topic="Supporting MIX and MUC together" anchor="mix-and-muc-together">
  <p>
   If both MIX and MUC are implemented, three approaches are noted.
  </p>
  <ol>
    <li>Entirely separate MIX and MUC implementation, with MIX and MUC using separate domains and MIX channels being completely separate from MUC rooms.</li>
    <li>Fully integrated MIX and MUC implementation, with MIX and MUC sharing a single domain and rooms/channels equivalent.</li>
    <li>Partially integrated MIX and MUC implementation, with MIX and MUC using separate domains, but all rooms/channel are common.  This means that each MIX channel will have MUC room of the same name and same participants. </li>
  </ol>
  <p>The fully integrated approach would be transparent to clients.      The following example shows how a service that supports MIX and MUC in a fully integrated manner would respond following the specification of &xep0369;:</p>
  <example caption="Client uses Disco to show fully integrated MIX and MUC support" ><![CDATA[
<iq from='hag66@shakespeare.example/UUID-c8y/1573'
    id='lx09df27'
    to='mix.shakespeare.example'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
</iq>

<iq from='mix.shakespeare.example'
    id='lx09df27'
    to='hag66@shakespeare.example/UUID-c8y/1573'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <identity
        category='conference'
        name='Shakespearean Chat Service'
        type='text'/>
    <feature var='urn:xmpp:mix:core:1'/>
    <feature var='http://jabber.org/protocol/muc'/>
    <feature var='urn:xmpp:mix:core:1#searchable'/>
  </query>
</iq>
]]></example>
  <p>In the fully integrated service item discovery on the MIX/MUC service determines a list of channels.   The protocol used for this is the same in MUC and MIX.   Discovery actions on a channel in MIX MUST use 'node=mix' attribute in the discovery which will lead to the return of MIX channel specific information, as mandated for this discovery in &xep0369;.   If is not set, MUC room specific information is returned.
  </p>
  <p>For the partially integrated service, MIX servers will reference the associated MUC server and MUC servers will reference the associated MIX service.   This will allow a client that only support MUC or only supports MIX to find the right server if it is given a reference to the other one.  For a client that supports both MUC and MIX, it will enable the client to select its preferred service.
    For a MIX client, it will also be useful to know the MUC service, so that this information can be shared with a MUC client invitation.
   The following example shows how a MIX server identifies the associated MUC server.  Note that MUC MUST NOT be advertized as a feature:

  </p>
  <example caption="Client uses Disco to find MUC server assocated with MIX server" ><![CDATA[
<iq from='hag66@shakespeare.example/UUID-c8y/1573'
    id='lx09df27'
    to='mix.shakespeare.example'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#info'/>
</iq>

<iq from='mix.shakespeare.example'
    id='lx09df27'
    to='hag66@shakespeare.example/UUID-c8y/1573'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <identity
        category='conference'
        name='Shakespearean Chat Service'
        type='text'/>
    <feature var='urn:xmpp:mix:core:1'/>
    <x xmlns='jabber:x:data' type='result'>
      <field var='FORM_TYPE' type='hidden'>
        <value>urn:xmpp:mix:muc:0#muc-mirror</value>
      </field>
      <field var='muc-mirror'
             type='jid-single'
             label='Location of MUC mirror service'>
        <value>chat.shakespeare.example</value>
      </field>
    </x>
  </query>
</iq>
]]></example>
    <p>The result is returned in an extended disco results in a form whose type value is 'urn:xmpp:mix:muc:0#muc-mirror'.  The  field with var='muc-mirror' is the value of which is the mirrored MUC domain's JID.  </p>
  <p>Similarly, a MUC service can advertise an associated MIX doming.   The following example shows discovery of a MUC domain.  Note that MIX MUST NOT be advertized as a feature</p>
  <example caption="Client uses Disco to find MIX server assocated with MUC server" ><![CDATA[
<iq from='hag66@shakespeare.example/UUID-c8y/1573'
    id='lx09df27'
    to='mix.shakespeare.example'
    type='get'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
</iq>

<iq from='chat.shakespeare.example'
    id='lx09df27'
    to='hag66@shakespeare.example/UUID-c8y/1573'
    type='result'>
  <query xmlns='http://jabber.org/protocol/disco#info'>
    <identity
        category='conference'
        name='Shakespearean Chat Service'
        type='text'/>
    <feature var='http://jabber.org/protocol/muc'/>
    <x xmlns='jabber:x:data' type='result'>
      <field var='FORM_TYPE' type='hidden'>
        <value>urn:xmpp:mix:muc:0#mix-mirror</value>
      </field>
      <field var='mix-mirror'
             type='jid-single'
             label='Location of MUC mirror service'>
        <value>mix.shakespeare.example</value>
      </field>
    </x>
  </query>
</iq>
]]></example>
  <p>The result is returned in an extended disco results in a form whose type value is 'urn:xmpp:mix:muc:0#mux-mirror'.  The  field with var='mix-mirror' is the value of which is the mirrored MIX domain's JID.  </p>
  <section2 topic="Choosing Which Invite to Send" anchor="mix-muc-invite-choice">
    <p>
      Where a client supports MUC and MIX and has determined that for a channel that the server also supports a MUC room, the client has a choice as to which type of invite to send.   This SHOULD be done by determining if the client support MIX using the mechanism specified in
       &xep0369;.  If the client supports MIX a MIX invite SHOULD be sent.
    </p>
  </section2>

</section1>


<section1 topic='Internationalization Considerations' anchor='i18n'>
  <p>See considerations in &xep0369;.
  </p>

</section1>

<section1 topic='Security Considerations' anchor='security'>
  <p>See considerations in &xep0369;.</p>

  <p>
    When converting a 1:1 conversation to a channel there is potential to expose sensitive information and to present invalid information.
  </p>

</section1>

<section1 topic='IANA Considerations' anchor='iana'>
  <p>None.</p>
</section1>

<section1 topic='XMPP Registrar Considerations' anchor='registrar'>
  <p>The urn:xmpp:mix namespace needs to be registered.</p>
</section1>

<section1 topic='XML Schema' anchor='schema'>
  <p>To be supplied when MIX progresses to proposed standard.</p>
</section1>

<section1 topic='Acknowledgements' anchor='ack'>
  <p>See &xep0369; for a list of contributors to the MIX Family of specifications.</p>
</section1>

</xep>